DESCRIPTION

ident_lookup
tries to connect to a remote
IDENT
server to establish the identity of the peer connected on
fd,
which should be a socket file descriptor.
timeout
is the longest permissible time to block waiting for an answer, and is
given in seconds. A value of 0 (zero) means wait indefinitely (which in the
most extreme case will normally be until the underlying network times out).
ident_lookup
returns a pointer to an
IDENT
struct, which has the following contents:

All data returned by
ident_lookup
(including the
IDENT
struct) points to malloc'd data, which can be freed with a call to
ident_free.ident_lookup
returns 0 on error or timeout. Presently, this should normally be taken to
mean that the remote site is not running an
IDENT
server, but it might naturally be caused by other network related problems
as well.
Note that
all fields of the
IDENT
struct need not necessarily be set.

ident_id
takes the same parameters as
ident_lookup
but only returns a pointer to a malloc'd area containing the
identifier
string, which is probably the most wanted data from the
IDENT
query.

ident_free
frees all data areas associated with the
IDENT
struct pointed to by
id,
including the struct itself.

Low-level calls

The low-level calls can be used when greater flexibility is needed. For
example, if non-blocking I/O is needed, or multiple queries to the
same host are to be made.

id_open
opens a connection to the remote
IDENT
server referred to by
faddr.
The timeout is specified by
timeout.
A null-pointer means wait indefinitely, while a pointer to a
zero-valued
timeval
struct sets non-blocking I/O, in the same way as for
select(2).id_open
returns a pointer to an
id_t
datum, which is an opaque structure to be used as future reference
to the opened connection. When using non-blocking I/O it might however
be useful to access the underlying socket file descriptior, which
can be gotten at through the
id_fileno
macro described below.

id_close
closes the connection opened with
id_open
and frees all data associated with
id.

id_query
sends off a query to a remote
IDENT
server.
lport
and
fport
are sent to the server to identify the connection for which
identification is needed.
timeout
is given as for
id_open.
If successful,
id_query
returns the number of bytes sent to the remote server. If not, -1 is
returned and
errno
is set.

id_parse
parses the reply to a query sent off by
id_query
and returns information to the locations pointed to by
lport, fport, identifier, opsys
and
charset.
For string data
(identifier, opsys
and
charset)
pointers to malloc'd space are returned.

id_parse
returns:

1

If completely successful.

-3

Illegal reply type from remote server.
identifier
is set to the illegal reply.

-2

Cannot parse the reply from the server.
identifier
is normally set to the illegal reply.

-1

On general errors or timeout.

0

When non-blocking mode is set and
id_parse
has not finished parsing the reply from the remote server.

2

Indicates the query/reply were successful, but the remote server
experienced some error.
identifier
is set to the error message from the remote server.

For all errors,
errno
is set as appropriate.

id_fileno
is a macro that takes an
id_t
handle and returns the actual socket file descriptor used for
the connection to the remote server.

ERRORS

ETIMEDOUT

The call timed out and non-blocking I/O was not set.

EXAMPLES

Here's an example how to handle the reply from id_reply() in
the case that non-blocking I/O is set. Note that id_reply() will
return 0 as long as it's not finished parsing a reply.